Multilayered device for controlled topical delivery of therapeutic agents to the skin

Abstract

A multilayered composite sheet for delivering one or more therapeutic agents to the skin is disclosed. The composite sheet comprises a flexible porous polymer with open cells of a sufficient size for holding a therapeutic agent, an encapsulating agent for encapsulating the flexible porous polymer and therapeutic agent, and an enrobing agent for enrobing the encapsulated flexible porous polymer and therapeutic agent. Additional layers of the flexible porous polymer, therapeutic agent and other materials are added to the first layer which is in contact with the skin. The first layer has particular particle sizes for the flexible porous polymer, open cell size, and therapeutic agent allowing for relatively quick delivery of the therapeutic agent to the skin. Each successive layer placed on top of the first layer has incrementally larger particle sizes of the flexible porous polymer and therapeutic agent providing successively longer delivery times than the first layer.

The invention claimed is: 
     
       1. A multi-layered delivery device, which is applied to the surface of skin for delivering one or more therapeutic agents to the skin, comprising:
 a first layer that contacts the skin, a second layer that contacts the first layer and a third layer that contacts the second layer, each layer comprising;
 particles of one or more therapeutic agents 
 particles of flexible, porous, encapsulated polymer open cell foam material, which material is selected from the group consisting of polyurethane, polyvinylacetate, polyvinylalcohol, polyethylene, and silicone for holding and releasing the therapeutic agent; 
 
 a polymer enrobing material selected from the group consisting of silicone, hyrogels ethylene vinyl acetate, and polyurethane elastomers for holding and releasing the encapsulated polymer foam material including the therapeutic agent for delivery to the skin; 
 wherein the particle size of the one or more therapeutic agents and the particle size of the flexible polymer with the open cell size become incrementally larger as they are situated in layers contacting the skin and then successively placed outwardly away from the skin, so that a smaller particle size of the therapeutic agent is located in a layer closer to the skin, with the next larger particle size located in a layer adjacent to the layer closest to the skin. 
 
     
     
       2. The delivery device according to  claim 1  wherein the first layer with particles of flexible porous encapsulated polymer foam material having particle sizes ranging from 800 to 900 microns. 
     
     
       3. The delivery device according to  claim 1  wherein the second layer with particles of a flexible porous encapsulated polymer foam material having particle sizes ranging from 900 to 1400 microns. 
     
     
       4. The delivery device according to  claim 1  wherein the third layer with particles of a flexible porous encapsulated polymer foam material having particle sizes ranging from 1400 to 2500 microns. 
     
     
       5. The delivery device according to  claim 1 , wherein the particles of the therapeutic agent and the flexible porous polymer are encapsulated by an encapsulating agent. 
     
     
       6. The delivery device according to  claim 5 , wherein the encapsulating agent is selected from the group consisting of poly(2-hydroxy ethyl methacrylate), poly(N-vinyl pyrrolidone), poly(methyl methacrylate), poly(vinyl alcohol), poly(acrylic acid), polyacrylamide, poly(ethylene-co-vinyl acetate), polyethylene glycol), and poly(methacrylic acid). 
     
     
       7. The delivery device according to  claim 1 , wherein a polymer enrobing material enrobes the encapsulated flexible porous polymer and therapeutic agent. 
     
     
       8. The delivery device according to  claim 1 , wherein a plurality of microchannels pass through the flexible porous polymer and polymer enrobing material for holding and releasing particles of one or more therapeutic agents. 
     
     
       9. The delivery device according to  claim 1 , wherein the particle size of the flexible porous materials have a diameter of about 800 to about 2500 microns. 
     
     
       10. The delivery device according to  claim 1  wherein the first layer includes open cell sizes ranging from about 350 to 650 microns. 
     
     
       11. The delivery device according to  claim 1  wherein the second layer includes open cell sizes ranging from about 650 to 950 microns. 
     
     
       12. The delivery device according to  claim 1  wherein the third layer includes open cell sizes ranging from about 950 to 1500 microns. 
     
     
       13. The delivery device according to  claim 1 , wherein the delivery device has two layers. 
     
     
       14. The delivery device according to  claim 1 , wherein the delivery device has a plurality of layers for containing therapeutic agents for treating the intended disease, dermatological condition, wound, or scar. 
     
     
       15. The delivery device according to  claim 1 , wherein the therapeutic agent is selected from the group consisting of polymixin B sulphate, fusidic acid, bacitracin zinc, gramicidin, silver, aminoglysosides, and silver sulphadine. 
     
     
       16. The delivery device according to  claim 1 , wherein the therapeutic agent is an antioxidant selected from the group consisting of vitamin E, vitamin C, ascorbyl palmitate, butylated hydroxyanisole, butylated hydroxytoluene and sodium bisulfate. 
     
     
       17. The delivery device according to  claim 1 , wherein the therapeutic agent is a therapeutic oil selected from the group consisting of lavender oil, rose hip oil, aloe vera and emu oil. 
     
     
       18. The delivery device according to  claim 1 , wherein the therapeutic agent is a hormone. 
     
     
       19. The delivery device according to  claim 1 , wherein the therapeutic agent is a steroid selected from the group consisting of corticosteroids, triamcinolone and dexamethasone. 
     
     
       20. The delivery device according to  claim 1 , wherein the therapeutic agent is a pharmaceutical selected from the group consisting of platelet-derived growth factor and pirfnedine.